Thermal optics are in cameras and scopes, basically anything we humans put over our eyes to allow us to see in thermal vision are thermal optics. When people think of thermal optics they think of military use, when actaully thermal imaging is widely used. Firefighters use it to locate humans/ pets from smoky builings, engingeers use it to locate any leaks in heating units or cooling units (air conditioners/ furnaces).
So how does it work? The first thing we must know is that ALL objects above absolute zero (lowest termperature possible) emit radition. Very simply, thermal optics capture this radiation and produce images known as thermograms. This makes it possible for us humans to see our surroundings in pitch black with no visible illuminatinon.
Detecting Temperatures Thermal optics can also detect the temperature of the image they are producing. They do this not by taking a reading of the object it-self but reading the temperatures around the object to determine the objects temperature. To do this, 3 types of energy have been clearly layed out: 1.Emitted energy- this is the energy given off by the object you are trying to take the temperture of. 2.Transmitted energy- this it the energy that passes through your object from the thermal imaging camera. 3.Reflected energy- this is the energy that reflects of the surface of your object and back to the thermal camera.
So in conclussion if your object is radiating at a higher temperature than its surroundings, the transfer of energy will be from hot to cold. In your thermogram, if you find a cool area that area is not actually "cold" but is absorbing a small amount of heat emitted by the hot object. The ability for objects to absorb or emit radiation is called emissivity.
Emissivity we now know that emissivity is the ability for an object to emit or absorb radiation. What we should know next is that every material has a different emissivity. Scientists use a scale that has ratings from 0.00-1.00. 0.00 means completly not emitting to 1.00 or completely emitting.
So how does it work?
The first thing we must know is that ALL objects above absolute zero (lowest termperature possible) emit radition. Very simply, thermal optics capture this radiation and produce images known as thermograms. This makes it possible for us humans to see our surroundings in pitch black with no visible illuminatinon.
Detecting Temperatures
Thermal optics can also detect the temperature of the image they are producing. They do this not by taking a reading of the object it-self but reading the temperatures around the object to determine the objects temperature. To do this, 3 types of energy have been clearly layed out:
1.Emitted energy- this is the energy given off by the object you are trying to take the temperture of.
2.Transmitted energy- this it the energy that passes through your object from the thermal imaging camera.
3.Reflected energy- this is the energy that reflects of the surface of your object and back to the thermal camera.
So in conclussion if your object is radiating at a higher temperature than its surroundings, the transfer of energy will be from hot to cold. In your thermogram, if you find a cool area that area is not actually "cold" but is absorbing a small amount of heat emitted by the hot object. The ability for objects to absorb or emit radiation is called emissivity.
Emissivity
we now know that emissivity is the ability for an object to emit or absorb radiation. What we should know next is that every material has a different emissivity. Scientists use a scale that has ratings from 0.00-1.00. 0.00 means completly not emitting to 1.00 or completely emitting.
In conclussion, thermal optics allow us humans to see our surroundings in pitch black and can also be used to detect an objects temperature. If you think owning a pair of these would be sweet and are thinking of buying a pair, you better have an extra 6-8 thousand dollars kickin around.
References:
http://en.wikipedia.org/wiki/Thermography
http://www.jdsu.com/en-us/Custom-Optics/applications/night-vision-thermal-imaging/Pages/default.aspx
By: Brydon